To make the unfair copying or reading of a bar code difficult.
In this method, a process in which a photosensitive layer 1 whose surface is defined as the incident plane 2 of light and the rear surface is defined as the reflection surface 3 of light is arranged so that the layer may relatively move for a light source and the light transmissivity member 8 of the refractive index which is almost equal to that of photosensitive layer 1 is arranged on the incident plane side of the photosensitive layer 1 and a process in which light beam 4 for record is irradiated from the light source at the incident angle for record which is inclined to the incident plane 2 by a fixed angle, interference fringes 5 are generated within the photosensitive layer 1 by reflecting the light beam 4 for record which is made incident from the incident plane 2 on the rear surface and the inteference fringes 5 are recorded on the photosensitive layer 1 are included. Further, a process in which light beam 4 for record is intermittently irradiated from the light source, relatively moving the photosensitive layer 1 for the light source and a bar code is recorded at the location of the photosensitive layer 1 along the moving direction of light beam 14 for record and a process in which the bar code recorded by the diffracted light beams of wavelengths of 780nm or more which can be obtained by irradiating the photosensitive layer 1 with light beam 10 for reading at an incident angle for reading is read are included.
KAI YASUAKI
SHINODA MASATO
IKUI SHUICHI
NISSAN MOTOR